Self-powered toilet turns human waste into clean water

14th of April 2015

Scientists are developing a toilet that turns urine into water and solid waste into energy.

The nano membrane toilet is being developed at Cranfield University in the UK. Water produced in the unit is sufficiently clean to be used for washing clothes or irrigating fields. The solid waste, meanwhile, is burned and transformed into energy.

And the heat from the burnt waste produces sufficient electricity to power the unit - while also charging the user's mobile phone.

Funded by the Bill and Melinda Gates Foundation, the toilet could bring sanitation to the homes of 2.5 billion people in countries where water supplies and sewage pipes are limited.

"It is a household-scale toilet that produces clean water and manageable, pathogen-free, disposable waste," said PhD student working on the project Jake Larsson. "It is self-standing, small enough to fit into someone's home and there's even a bit of energy left over to charge a mobile phone.

"Not only it is for developing countries, it's also useful for developed countries maybe for the military or for the construction industry." The unit could also be used as an odour-free alternative to music festivals toilets, claims the team.

Once the lid is closed, the bowl rotates and carries the waste into a holding tank. This is said to maintain an "odour barrier" that prevents smells.

The nano membrane separates the liquid waste which can be used for irrigating fields or washing clothes. It could even be made clean enough to drink. Meanwhile the solid waste is passed into a gasifier which burns it, producing ash which can be used for agriculture. The Cranfield University team aims to start field testing the toilet in 2016.